What is 840 Divided by 21 using Long Division?

$$ \begin{array}{rl} & 040 \phantom{00} \leftarrow Quotient \\[-4pt] Divisor \rightarrow \phantom{0} 21 \kern-1ex & \kern-1ex \enclose{longdiv}{840} \phantom{0} \leftarrow Dividend \\[-4pt] & \phantom{} \underline{\phantom{} 0\phantom{0}} \\[-4pt] & \phantom{} 8 4 \\[-4pt] & \phantom{} \underline{\phantom{} 84\phantom{0}} \\[-4pt] & \phantom{0} 0 0 \\[-4pt] & \phantom{00} \underline{\phantom{} 0\phantom{0}} \\[-4pt] & \phantom{00} 0 \phantom{0} \leftarrow Remainder \\[-4pt] \end{array} $$